Julian and Gregorian Calendar Calculator

Converts between Julian and Gregorian calendar dates.

Julian and Gregorian Calendar
    1. Calendar

Julian and Gregorian Calendar
The Gregorian calendar is used for dates on and after October 15, 1582 AD.
    Julian and Gregorian Calendar
    [1-10] /23Disp-Num
    [1]  2021/10/25 21:47   40 years old level / Others / Very /
    Purpose of use
    it's kind of a mess caused by a mere coincidence.

    i was trying to figure out the lunisolar date of a solar term in the Middle Ages. any solar term is around a certain date based on the Gregorian calendar, so it's easy to guess. as converting the Gregorian date to the lunisolar one, it turns out to be on the date of full moon (the 15th of each month). it made me curious about the sky map of that day. however my software shows the moon far over from full. i know there's approximately a 9-day gap between the Gregorian and Julian over that time, but 9 days ago it was still not a full moon -- two days before full. although the lunisolar calendar tends to have a "one day earlier" error near full moon, two days seem too much. i felt not sure about my calculation between the Gregorian and Julian, so here i'm... now i understand the full moon error of the lunisolar calendar could be more than one day as long as it sets the new moon to be the 1st of each month.

    btw, there're a lot of software and apps using the Julian calendar by default. beside the one mentioned above, the solar term table i found on the internet is also presented in the Julian date. without some other references to crosscheck you'd never notice it and take it as the Gregorian date as granted. so i feel your calculator is far more useful than it looks.
    [2]  2021/09/24 01:58   60 years old level or over / A retired person / Very /
    Purpose of use
    Genealogy related. To find Gregorian date from Catholic Church Book Records(Julian) from Russian occupied Poland (Ukraine).
    This is very useful. I have bookmarked your page.
    [3]  2021/09/02 06:50   Under 20 years old / High-school/ University/ Grad student / Useful /
    Purpose of use
    To go back and forth between the Orthodox Christian calendar (which uses the Julian calendar) and the Greogorian calendar
    [4]  2021/08/15 20:58   60 years old level or over / Others / - /
    Purpose of use
    To take control of my life
    [5]  2021/06/30 18:24   20 years old level / High-school/ University/ Grad student / A little /
    Purpose of use
    Attempting to convert from ancient Egyptian to Coptic to Gregorian to Julian because SOMEBODY apparently thinks Atem Yugioh's birthday is June 2nd because something something flooding of the Nile, even though the ancient Egyptian calendar certainly was NOT calibrated to the modern flooding of the Nile, and the calendar in use during the year of Atem's birth (if we consider him to have been born 3016 years before the events of Yugioh, first published in 1996) was basically just the Coptic calendar without a leap day.
    [6]  2021/06/25 04:37   20 years old level / An engineer / Useful /
    Purpose of use
    Validating a historical calendar implementation that can express arbitrary timelines of calendar system switches, interpret and stamp back out dates as they would have been written at the time.
    [7]  2021/06/11 12:47   20 years old level / High-school/ University/ Grad student / Very /
    Purpose of use
    Checking to see how you could calculate Julian date from Gregorian date for reference for a fanfiction I'm writing regarding a time traveler going to Rome and needing to convert back and forth between calendars, very helpful, thank you
    [8]  2021/02/16 22:53   60 years old level or over / A retired person / A little /
    Purpose of use
    Checking on comparative saints' days, trying to figure out why different sources don't agree! (Retired & researching university prof)
    [9]  2021/02/05 23:26   50 years old level / An office worker / A public employee / Useful /
    Purpose of use
    Converting names day date from Julian to Gregorian equivalent.
    [10]  2020/11/01 04:35   30 years old level / Others / Useful /
    Purpose of use
    Finding the Gregorian date for the beginning of Saturnalia.


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